Guild File Reference

Guild File Format

Guild files are named guild.yml. They contain Guild AI related project configuration. This document describes their format and schema.

Guild files are plain text, YAML formatted files.

Guild files support two different formats:

  • Full format
  • Operation-only format

Use the format best suited to your requirements. See What Format to Use below for suggestions.

Full Format

Full format mode uses a list of top-level objects in the format:

- object_type: name
  attr_1: val_1
  attr_2: val_2

- object_type: name
  attr_1: val_1
  attr_2: val_2

object_type is an attribute that implies the object type by its presence. The attribute value is the object identifier, or name.

Guild supports the following object types in full format:

  • model

    Models define operations, which are run to generate experiments. See Models below.

  • config

    A named mapping of attributes that can be referenced by other top-level objects as configuration. See Config below.

  • package

    Packages define how Guild generates Python wheel distributions. See Packages below.

If a top-level object doesn’t contain an object type attribute, Guild assumes model with an empty name. A model with an empty name is referred to as an anonymous model.

The following example defines three top-level objects using full format:

- package: mlp-pkg
  version: 0.1

- config: shared-flags
    lr: 0.1
    batch-size: 100

- model: mlp
        $include: shared-flags

Operation-Only Format

Operation-only format is a simplified format that contains a map of operations in the format:

  attr_1: val_1
  attr_2: val_2

  attr_1: val_1
  attr_2: val_2

Operation-only format is equivalent to full format consisting of a single model with an empty name (i.e. an anonymous model). The example above is equivalent to:

- model: ''
    operation_name_1: ...
    operation_name_2: ...

Which Format to Use

Use full format when you want to:

  • Specify a model name
  • Define multiple models
  • Define model attributes like resources and sourcecode
  • Define a package

Use operation-only format when you want to:

  • Only define operations, keeping the Guild file as simple as possible

Users often start with operation-only format and move to full format as needed.

Here’s a simple operation-only Guild file:

  main: prepare
    val-split: 0.2

  main: train
    learning-rate: 0.1
    batch-size: 100

To convert to full format, move the operations to a top-level model object:

- model: mlp
      main: prepare
        val-split: 0.2

      main: train
        learning-rate: 0.1
        batch-size: 100


An operation tells Guild what to do when you execute guild run. For information on using operations, see Operations.

Define operations in Guild files using either operation-only format or full format. Each operation is a map of attributes.

The following is an example of operation train with three attributes: description, main, and flags:

  descrition: Train a CNN image classifier
  main: cnn
    layers: 3
    dropout: 0.2
    epochs: 100

Operation Attributes

<mapping key>

Operation name (required string)

An operation name is a mapping key. If the Guild file is written in operation-only format, the mapping is defined at the top-level of the Guild file. If the Guild file is written in full format, the mapping is the value of the operations attribute for a model.

Use an operation name to run operation. If the operation is defined for a named model (full format only), you can refer to it as MODEL_NAME:OPERATION_NAME. Otherwise refer to it as OPERATION_NAME. The model name in this case is empty and can be omitted.


Operation description (string)

This value can span multiple lines. By convention, the first line is a short description that does not end in a period. Subsequent lines, separated by an empty line, should be written using full sentences.


Flag indicating that the operation is default (boolean)

Guild runs the default operation if an operation name is not specified. If there is only one operation, it is always considered as the default.


Operation main Python module (string)

This value tells Guild what to execute when someone runs the operation. The value must be in the format:


MODULE_PATH must be specified if the module is located in a non-package subdirectory relative to the Guild file. When defined, Guild includes MODULE_PATH in the Python system when running MODULE. MODULE is the full module name including any parent Python packages.

ARG is argument that should be passed to the module. Specify multiple ARG values as you would when running the module with Python. You must quote arguments containing spaces to ensure they are passed to the module correctly.

Guild appends flag arguments after the main spec as --FLAG_NAME FLAG_VAL.

You can explicitly specify flag values using the format ${FLAG_NAME}. Guild replaces these references with corresponding values when creating the command. Note that unless arg-skip is true for referenced flags, those values will also be appended as argument as per above.

Do not include the .py extension in the value for MODULE.

main is used for Python modules only. To run a program using a different language runtime or to otherwise control the command that Guild runs, use exec.


Operation command (string)

Guild uses this value to execute a system command. Use exec to run non-Python operations or when you want to control the command that Guild uses to run the operation.

Use exec to run operations by executing a program. By default, flags are not included in the operation command. To include all flags in the format --FLAG_NAME FLAG_VAL, specify ${flag_args} in the position you want the arguments included in the command. Otherwise specify flag values using the format using the format ${FLAG_NAME}.


List of steps to run for workflow (list of strings or steps)

Steps are used to implement sequential work flow in Guild. Refer to Steps below for details.


Operation flags (mapping of flag name to flag)

Flags are user-definable values used for an operation. Mapping keys are flag names. See Flags for a list of flag attributes.


Destination for flag values (string)

This value tells Guild how to communicate flag values to the operation script. Guild supports the following flag destinations:

  • args

    Provide flag values as command line arguments.

  • globals

    Set flag values as global variables (Python modules only).

  • global:DOTTED_NAME

    Set flag values as dict values in DOTTED_NAME (Python modules only).

    DOTTED_NAME is a series of keys where each key separated by a dot (.) Guild sets each flag value in a Python dict that is resolved by reading module namespace attributes starting with the root namespace and proceeding from left-to-right along the series. For example, the value global:params sets flag values in a global dict named params. The value global:params.train sets values in a dict defined as the attribute or key train of the global variable params.

  • dict:DOTTED_NAME

    Alias for global:DOTTED_NAME. See above for details.

  • namespace:NAME

    Set flag values in a SimpleNamespace global variable (Python 3 modules only).

    NAME is the name of the global namespace variable.

    Simple namespaces in Python are objects that provide attribute access to parameters. This destination type is similar to global dictionaries where parameters are access using Python dict access (e.g. params['foo']) but instead use attribute access (e.g.

For a list of working examples, refer to the examples/flags project.


List of flags to import (string or list of strings)

This attribute applies only when main is used to run a Python module.

By default, Guild does not import any flags. To import all detected flags, use yes or all for the value.

To import a list of flags, specify a list of flag names.

When importing flags, Guild inspects the script specified in the main attribute to determine how flags are defined. If the Python module uses argparse, Guild inspects the parser arguments for flags, otherwise it inspects the module for global scalar or string assignments. This interface can be controlled explicitly using flags-dest.


List of flags to skip when importing all flags (list of strings)

This attribute applies only when main is used to run a Python module.

Use when setting flags-import to yes or all when it’s more convenient to exclude a list of flags than it is to list flags to import.


List of required resources (list of resources)

By default run directories are empty. Project files that a script needs are not available by default. To ensure that a script can access to required resources, define them using this attribute.

Resources can be named or inline. Named resources are defined by a model resources attribute and referenced using their name. Named resources can be shared across operations. Inline resources are defined as a requires attribute item. See Resources for details.


Specification used to copy source code files (source code spec)

Guild copies source code for each run to provide a record associated with the run. Python based operations are isolated from their upstream project source code and rely on copied source code.

By default, Guild copies text files that are less than 1M up to 100 files. Guild shows warnings for files that exceed these limits.

When the sourcecode attribute is defined, Guild does not apply these checks.

See Source Code for details.


List of output scalar patterns to apply to run standard output (list of output scalar specs or no)

By default, Guild captures output scalars using the pattern ^(\key): (\value).

Use the output-scalars attribute to customize the way Guild captures scalars from standard output.

To disable capturing of output scalars altogether, specify no.


Additional environment variables available to the operation process (mapping of names to values)

Flag values are always available in the environment as FLAG_NAME variables, where NAME is the upper case flag name with non-alphanumeric characters converted to underscores. A flag can specify a different environment variable name using the env-name flag attribute.


Like env but values are not saved as run metadata (mapping of names to values)

Use to specify environment variables in the same way that env is used. Values defined by this attribute are not stored in the env run attribute. Use this as a safeguard to ensure that secrets aren’t stored with a run.


Path to use for PYTHONPATH when running the operation (string)

Use when you need to include additional system paths for a Python based operation.


Indicates whether user-termination of the operation should be treated as a success (boolean)

By default, Guild designated user-terminated operations as terminated. In some cases, you may want to designate such user-terminated operations as completed. In this case, set this attribute to yes.


Label template for the operation (string)

By default, Guild creates a label that includes user-provided flag values. Use the label attribute to to define an alternative default label template.

Use ${FLAG_NAME} in the label to include specific flag values.


Tags to use for the run (list of strings)

Tags specified when the operation is run are added to the list specified in the Guild file.


List of columns to include for operation runs in Guild Compare (list of column specs)

Use to define only the columns that are useful for comparison when an operation has a large number of flags or scalars.


Default number of max trials when running batches (integer)

By default, the max trials used when the user doesn’t explicitly specify --max-trials is optimizer-specific. All of Guild’s built-in optimizers have a default max trials of 20. Use to define a different default.


Objective used by sequential optimizers (string or mapping)

If objective is a string, optimizers attempt to minimize the specified scalar value for runs. This is equivalent to the mapping minimize: SCALAR.

To maximize a scalar, precede the attribute value with a negative sign -. This is equivalent to the mapping maximize: SCALAR.


Mapping of named optimizers associated with the operation

The mapping is of names to optimizer attributes. A name can be used for a run by specifying it with the --optimizer option with guild run.

By default, the name is used as the optimizer operation. For example, a mapping key of gp uses the gp optimizer. You can use a different optimizer by defining the special algorithm attribute. As with any optimizer, the value for algorithm can be a project defined operation.

You can also define the special default attribute, which indicates if the optimizer is used when the operation is run with the --optimize option.


List of plugins to enable for the operation

Use the value all to enable all plugins. To enable all summary-related plugins (cpu, gpu, disk, memory, and perf) use the value summary. See Plugins Reference for more information.


Whether pip freeze is run for an operation (boolean)

When this flag is set, Guild generates a pip_freeze run attribute containing the output of the pip freeze command.

This flag is set by default for Python based operations. To disable it, set the value to no.


Default value for flag arg-skip attributes (boolean)

Set this value to yes to omit flags from command line arguments when flags-dest is args. You can re-enable specific flag arguments by setting their arg-skip attribute to no.


Delete the run if it succeeds (boolean)

Set this value to yes to cause Guild to delete runs for this operation when the succeed. Non-successful runs (e.g. runs that terminate with a non-zero exit code or that are terminated by an interrupt) are not deleted, regardless of this attribute.

There may be cases where a run performs an action that is recorded elswhere (e.g. logged externally) and there is little value in keeping the run when it succeeds.

This setting can be overridden using --keep-run with the run command.


Flags are defined as mappings under the flags operation attribute. The mapping key is the flag name.

A mapping value can be either a mapping of attributes or a default value. Supported flag attribute are listed below.

Guild supports the special $include mapping key, which can be a string or list of strings. Each string can refer to either a model operation or a config object. See Reuse Flag Definitions below for more information.

Flag Attributes

<mapping key>

Flag name (required string)

The flag name is used when specifing a flag value. When specifying a value as an argument to the guild run command, the name is used as FLAG_NAME=VALUE.


Flag description (string)

The flag description is used in project and operation help. If the flag description contains more than one line, the first line is displayed for operation help (e.g. when guild run OPERATION --help-op is run). The full string is displayed for project help (e.g. when guild help is run for a project).


Flag value type (choice — see options below)

Flag type is used to both validate and convert flag values when set as global variables. Note that all command line arguments and environment variables are passed as strings and must be converted by the script. Guild uses flag type to validate user-provided input in all cases.

When type is not specified, Guild converts user-input to values using YAML rules for decoding.

Supported types:

  • string

    Value is converted to string regardless of how it would be decoded as YAML.

  • number

    Value is converted to an integer when possible, otherwise it is converted to a float.

  • float

    Value is converted to a float.

  • int

    Value is converted to an integer.

  • boolean

    Value is converted to a boolean.

  • path

    Value is converted to a string and must contain only valid path characters.

  • existing-path

    Value is converted to a string and checked as an existing path.


Default flag value

By default, flag values are null and are not passed to the script. Users override a default value when running an operation using the form guild run OPERATION FLAG_NAME=VALUE.


Whether a flag value is required (boolean)

By default, flag values are not required.


Argument name used when setting the flag value (string)

If operation flags-dest is args, this attribute specifies the argument option name, used as --NAME VALUE.

If operation flags-dest is globals, this attribute specifies the global variable name.

If operation flags-dest is global:PARAM, this attribute specifies the key used when setting the flag in the PARAM global dict. In this case, dots (.) in the name denote nested entries in the global dict. For example, the value for a flag with arg name will be set in the dict PARAM so that it can be read as PARAM["train"]["lr"].


Map flag values to command arguments (map of value to string)

Added in 0.8.2.

Use arg-encoding to change the command argument value for a specified flag value. A common case is to map boolean values (i.e. yes/no, true/false, etc.) to different encodings. By default, Guild encodes true as '1' and false as the empty string '' in support of Python’s bool() function. To specify different argument values for true and false, arg-encoding may be used this way:

      type: boolean
        yes: 'true'
        no: 'false'

Any values used from this attribute for command arguments are also used for the corresponding environment variable. To change the environment variable encoding, use env-encoding.


Indicates whether the flag is skipped as an argument (boolean)

By default, all flags are set according to the operations args-dest attribute. If arg-skip is set to yes for a flag, that flag will not be set.

Use to skip flag arguments that are specified in main or exec operation attributes to avoid duplicating them.


Flag value that, when specified, causes the flag to be set as a boolean switch

By default, Guild passes a flag on the command line in two parts in the format --FLAG_NAME FLAG_VAL. When arg-switch is defined, Guild passes the flag as a single part in the format --FLAG_NAME. This only occurs when the flag value equals the arg-switch value. If the value is not equal to arg-switch, Guild does not pass any arguments. This is referred to as a boolean switch.

A boolean switch is specified as True when set as a global variable.

For example, if arg-switch is yes for a flag named test, when the user specifies test=yes, the command line option --test is provided without a value to the script — or the global variable test is set to True — depending on the operation flags-dest setting.


Indicate whether or not a flag value is split into a string (boolean or string)

If arg-split is yes, Guild will split flag values into parts using shell like syntax and convey the flag value to the script as a list. arg-split may alternatively be a string. The special string shlex is equivalent to the boolean value yes. Any other string is used as a delimiter to split the flag value. The most common delimiter is a comma.

For example, it yes (or shlex) Guild splits the following flag x
assignment into a list [1, 2, 3]:

guild run x="1 2 3"

If arg-split is a comma , Guild splits the following flag x
assignment similarly:

guild run x=1,2,3


List of allowed flag values (list of values or mappings)

Each list item can be either a value, which indicates one of the valid choices, or a mapping of choice attributes.

When specified as a mapping, valid attributes are:

  • value

    Choice value

    The choice is ‘selected’ when the flag value equals this value. This value is used as the flag value unless arg-value is specified, in which case that value is used.

  • description

    Description of the choice

    The choice description is used when showing operation help.

  • alias

    Alternative value for selecting a choice

    If a choice alias is specified, the choice value is used for the flag value. Aliases are used in help text for the operation.

    The choice value can still be used to select the choice.

  • flags

    Mapping of flag names to values that are applied when the choice is selected

    Use flags to define a profile of flag values that is applied when the choice is selected.

    Note that the user can override flag values defined in flags by explicitly setting them for a run.


Indicates whether the user can enter a non-choice value when choices is specified (boolean)

By default, when choices is defined for an operation, Guild prevents the user from specifying values that are not in the list of choices. To allow non-choice values, set this attribute to yes.


The environment variable name used for the flag (string)

Use to defined an alternative environment variable name.

By default, Guild provides a flag value as the environment variable FLAG_UPPER_NAME where UPPER_NAME is the flag name in upper case. All non-alpha-numeric characters are converted to underscore characters. So a flag named learning-rate is available by default as the environment variable FLAG_LEARNING_RATE.


Map flag values to environment variable values (map of value to string)

Added in 0.8.2.

Use env-encoding to change the environment variable value for a particular flag value. This attribute serves the same function as arg-encoding but is applied to environment variables rather than command arguments.


Display label used in operation preview when flag value is null (string)

By default, Guild uses the string default when showing null values in the operation preview. Use in cases where another string would be clearer. For example, if the behavior of a script is to auto-detect a value when a dataset flag is null, null-label could be set to 'auto detected' to convey this to the user.


Minimum allowed value (number)

By default, Guild does not check number ranges.

This value also serves as the default lower bound for values chosen by optimizers.


Maximum allowed value (number)

By default, Guild does not check number ranges.

This value also serves as the default upper bound for values chosen by optimizers.


Distribution used when sampling values for flag (string - see below for options)

Legal values are:

  • uniform

    Sample from a uniform distribution.

  • log-uniform

    Sample from a log uniform distribution.


An operation can require resources to run. Required resources are also referred to as dependencies.

Required resources are specified using the requires operation attribute.

Dependencies can be inline or named. An inline resource is defined as part of the requires operation attribute. A named resource is defined as a model resource and is referenced using the resource name.

When defining an inline resource, use supported resource attribute (see below). You can include a name attribute that is used when referencing the inline resource. By default, Guild generates a unique name using the resource source URIs.

The following defines a list of both inline and named dependencies:

- model: cnn
        - file: data.csv      # inline resource
        - prepared-data       # refers to named resource, defined below

  resources:                  # named resoures
      - operation: prepare-data

If a resource is a mapping, it specifies resource attributes. If it’s a list, the list is assumed to be the value of resource sources.

Resource Attributes

<mapping key>

Resource name (string — named resource only)

If a resource is defined by a resources model attribute, the object mapping key is the resource name. If a resource is defined inline, use name to optionally define its name.


Resource name (string — inline resource only)

If a resource is defined inline, the name can be defined using this attribute.

Guild uses the resource name when referring to the resource. The name is also used to specify resource values using flag assignment syntax unless flag-name is defined.


List of sources to resolve (list of resource sources)

A resource conists of one or more sources, which are defined by this attribute. This attribute is implicitly defined when a resource is a list rather than a mapping.


Path under run directory in which resolved files are created (string)

Use to save resolved resource sources under a run subdirectory.

Backward Compatible Change This attribute is named path in versions prior to 0.7. Use target-path as a clearer alternative.


Type of file created when resolving resource sources (choice — see below for details)

Guild creates either file links or file copies when it resolves sources. This attribute is used to specify the default target type for sources. Each source can define this attribute to override the default. See resource source target-type for details.


Flag name used to specify resource values using flag assignment syntax (string)

Some resource sources support user-defined values using flag assignment syntax. For example, an operation source will use a run ID specified as NAME=VALUE where NAME is the resource name. You can use a different name for the flag assignment by defining flag-name.


Whether source archives are unpacked by default (boolean)

By default, archive sources (i.e. sources with known archive extensions such as .zip, .tar, etc.) are unpacked when resolved. To ensure that sources are not unpacked by default, set this attribute to no.

Each source can define unpack as needed to override this setting.


Resource description (string)

Optional resource description. Use this to document the resource. To list attribution sources, use references. This attribute is for annotation purposes and not otherwise used by Guild.


List of attributions or other references for the resource (list of strings)

Use to denote resource origins (e.g. papers, etc.) This attribute is for annotation purposes and not otherwise used by Guild.

Resource Source Attributes

<type attribute>

Use one and only one type attribute when defining a resource source.

    - <type attribute>: <value>
      # Other attributes

Local path relative to the Guild file (string)

A file can refer to a file or a directory.


Network accessible file (string)

This must be a valid URL.


Files generated by an operation (string)

Value is a regular expression matching a suitable operation name. Multiple operations are supported by specifying the appropriate regular expression.


Project file relative to the Guild file (string)

The file must be a supported type: JSON, YAML.

Guild resolves config sources by re-writing the files with any flag values that are different from those defined in the original file.


Required software library (string)

Guild resolves module types by verifying that a Python module is available for a run. Use this source type with a help message that provides instructions for installing the missing library.


Name used to reference the source (string)

By default, Guild uses the type attribute value to generate a name for the source.

If this attribute is not defined, the resource name can be used to to specify a source value. However, this only applies to the first source defined in for sources. Subsequent sources must define name to support user-defined values.


Path under which resolved source files are created (string)

By default, Guild creates links in the run directory. Use target-path to specify a subpath. This value overrides any defined by a parent resource.

Backward Compatible Change This attribute is named path in versions prior to 0.7. Use target-path as a clearer alternative.


Type of file created when resolving resource sources (choice — see below for options)

When Guild resolves a resource source, creates either a link to a source or a copy of that source. By default, Guild creates links.

Target type can be one of:

  • copy

    Guild creates a copy of the original source. Set this value for a source to ensure that changes to a source do not effect current runs.

  • link

    Guild creates a symbolic link to the original source. This value is assumed by default. Note however that this behavior will change in future versions of Guild (see note below). Consider using copy for sources that can change after a run.

Important This setting has implications for reproducibility. To ensure that a run has an accurate record of an operation, the value of target-type should be copy.

This will become the default behavior in future versions of Guild.

To avoid expensive copy operations for large resources that do not change, it is safe to use link.


SHA-256 digest used to validate a source file (string)

If specified, Guild calculates a SHA-256 digest for a resolved source and compares it to the attribute value. If the digests do not match, Guild stops the run with an error.

Use to ensure that a source does not change without detection.

If the source is a directory, Guild ignores this value and prints a warning message.

Tip Use guild download to download a remote resource (URL) and calculate it’s current SHA-256 digest. Use that value in the source definition to ensure that runs always use the expected source.

To calculate SHA-256 digests for a project file, use sha256sum or a similar program.


Whether Guild unpacks resolved archives (boolean)

By default, Guild unpacks resolved archives. Set this value to no disable unpacking.

If this attribute is not specified, Guild uses the resource default-unpack attribute, if defined.


List of patterns used to select files from an archive or directory (string or list of strings)

If a file path within an archive or directory matches one of the specified select patterns, that file is selected, otherwise the file is not selected.

Archives must be unpacked to select files.

This setting is ignored for single file sources.

select-min, select-max

Patterns used to select a file matching minimum or maximum captured value (string)

Use to select one file from a list of archive or directory files using a captured group value. For example, if a directory contains file-1 and file-2, the select-min value 'file-([0-9]+)' selects file-1. Similarly, select-max would select file-2.

Tip Use with operation source types to select saved models using minimum or maximum values from their file names. For example, if a model is saved with loss values in its file name, use select-min to select the file with the lowest loss using the applicable file name pattern.


Specification for renaming resolved files (string or mapping)

If the value is a string, it must be in the form PATTERN REPL where PATTERN is a regular expression to match and REPL is the value used to replace matched patterns.

If the value is a mapping, it must define the following attributes:

  • pattern

    The pattern to match (string)

  • repl

    The value to replace matching patterns (string)

Use in conjucntion with target-path to accommodate code that relies on a hard-coded path or otherwise control the run directory layout.


Command to run once to process a resource (string)

When Guild first resolves a resource, it runs post-process if specified. This command is run once per command value. If the value is changed, Guild will re-run the command when resolving the resoure.

Use to perform tasks on a resolved resource. For example, to apply patches, compile source, etc.


Whether to log a warning when source doesn’t resolve any files (boolean)

If true (default), Guild logs a warning message if the source does not resolve files. Set this to no to disable this warning.


Flag indicating that the source is optional (boolean)

Added in 0.8.2.

If true, Guild proceeds with a run when the source cannot be resolved. By default, sources are required, not optional, and Guild generates an error when the source cannot be resolved (e.g. a required file does not exist, a required run cannot be found, etc.) If a source is optional, set this value to true.


Whether a runs stops with an error when source doesn’t resolve any files (boolean)

If true, Guild exits with an error message when a source does not resolve files. By default, Guild logs a warning message (see warn-if-empty). Set this attribute to yes to prevent a run from continuing in such cases.


Message to show the user if the resouce cannot be resolved (string)

Use to give the user instructions for resolving the issue.

Source Code

The operation sourcecode attribute specifies how source code is copied for a run.

The attribute value can be a list, a mapping, or a string. If the value is a string, it’s used for root as if specified as a mapping.

If the value is a list, it’s used for select as if specified as a mapping. See Source Code Select Rules below details.

If the value is a mapping, it uses the attributes listed under Source Code Attributes below.

See also: Source Code Cheatsheet

Source Code Attributes


Alternative root from which to copy source code (string)

By default, Guild copies source relative to the Guild file defining the operation. Use root to specify an alternative path.

This value can use ../ to reference source code outside the Guild file directory.

Important Paths that refer to locations outside the Guild file directory can break if the project is copied to another system.


List of select rules

See Source Code Select Rules for a description of select rules.


Whether Guild generates a digest for copied source code (boolean)

By default Guild generates digests of copied source code. The digest can be used to determine if source code used by two runs is different.

In some cases, it can be too expensive to compute a digest and the source code version is available in a source code file. In such cases, you can disable the digest by setting this attribute to no.


Alternate destination directory for source code (string)

By default, Guild copies source code to .guild/sourcecode the run directory. Use dest to copy the source code to a different location. For example, to copy the source code to the run directory root, use the value . as the dest value.

Source Code Select Rules

Each select list, whether specified under select for a sourcecode mapping or as an item in a sourcecode list, is an include or exclude rule. Each rule is either a string or a mapping.

If the rule is a mapping, it must contain a type attribute of either include or exclude. The type attribute value is a glob style wildcard pattern or list of patterns.

If the rule is a string, it implies a mapping type of include where the string is the wildcard pattern.

When at least one rule pattern matches a path relative to the source code root (the Guild file location by default), Guild applies the rule with the effect of including or excluding the path according to the rule type attribute.

Rules are applied in the order specified. Subsequent rules override previous rules.

You can alternatively specify a mapping value for include or exclude. The mapping contains a single match type attribute, which indicates the type of match to apply. The value is a wildcard pattern or list of patterns.

Supported match type attributes are:

  • text

    Matches only text files

  • binary

    Matches only binary files (i.e. non-text)

  • dir

    Matches only directories

Excluding dir types has a performance benefit as Guild will not scan the contents of excluded directories.

Output Scalars

Output scalars are numeric values that are written to standard output or standard error streams during a run. Output scalar values correspond to a key and an optional step.

Guild supports output scalars as an alternative to explicit logging to summary logs. Use output scalars to log numeric results by printing them as script output.

Output is matched using regular expressions. Values are captured using capture groups. The special escape values \key, \value, and \step can be used to match keys, values, and step values respectively.

By default, Guild logs output written in the format:

key: value
  • key must not be preceded by any white space
  • value must be a value that can be decoded as number
  • Guild treats the key literal step as a special value, which is used to set the step associated with subsequently logged values

This scheme is designed for simple cases and can be modified using the output-scalars operation attribute.

The output-scalars attribute can be a mapping of scalar keys to capturing pattern or a list of capturing patterns. If the value of output-scalars is a mapping, the mapping keys correspond to scalar keys and each value is a pattern that captures a numeric value as a group.

If the value of output-scalars is a list, each item can be a mapping of keys to capturing patterns, which is treated identically as the mapping described above, or as strings. If an item is a string, it must define two capture groups. By default, the first capture group is the scalar key and the second capture group is the scalar value. Named capture groups can be used to reverse this order using _key and _value group names for the captured key and value respectively.

Patterns must be valid Python regular expression.

The special templates \key, \value, and \step represent regular expressions for valid keys, numeric values, and step values respectively.

Tip Use the --test-output-scalars option to guild run to test strings from generated output. You can test a file or interatively test strings that you type into the console (use - as the file name to read from standard intput).

Refer to Guild File Cheatsheet for output scalar configuration examples.


By default Guild shows all flags and root output scalars for an operation run in Guild Compare. Use the columns operation attribute to define an alternative set of columns.

Guild supports a special syntax for specifying a column, which is defined by the following grammar:

['first'|'last'|'min'|'max'|'total'|'avg'] SCALAR_KEY ['step'] ['as' DISPLAY_NAME]



A column can be renamed by appending as DISPLAY_NAME to the column expression.

To show a scalar, specify the scalar key. Note that scalars are logged per step and so can have multiple values. Each value is associated with a step. Specify how to summarize scalar values over all steps by preceding the expression with one of the qualifiers listed above (i.e. first, last, etc.) By default, Guild applies the last qualifier. This uses the scalar value associated with the largest step.

To show a run flag, prefix the flag name with an equals sign ('=').

To show a run attribute, prefix the attribute name with a dot ('.'). For a list of attributes, run guild ls -a -p .guild/attrs RUN.

Note Column specs are used with any column-spec command option. For example, use the above syntax for SPECS in guild compare --columns SPECS where each column spec is separated with a comma.


Steps are used to implement sequential work flow in Guild. The steps operation attribute specifies a list of operations to run.

Operations that define steps are referred to as pipelines.

A step is a string or a mapping. If a step item is a string, the value is used as run in a mapping.

Step Attributes


In operation to run for the step (string)

You can include flag values as arguments to the operation. Alternatively, use the flags attribute to list flag assignments.


An alternative name used for the step (string)

By default, the operation name specified for run (or as the step value if it is a string) is used as the name.

Names are used as links within the stepped run.


Flag values used for the step operation (mapping of flag names to values)

Use flags to specify flag values used for a step run. You can include references to step flag values as needed to pass through user-specified values.

Important This attribute defines flag values only. It does not define the flags themselves. Flags are defined by the operation being run.


List of checks to perform on the step (list of step checks)

Use checks to validate a step. Checks are used to implement tests in Guild.


Whether to limit visible runs to those generated by the step parent run (boolean)

By default, only runs generated by the step parent are visible to a step run. Set this value to false to consider runs generated outside the step parent when resolving operation dependencies for the step.

Other Step Run Options

In addition to the attributes above, a step supports the following run options:

  • batch-tag
  • fail-on-trial-error
  • force-flags
  • gpus
  • label
  • max-trials
  • maximize
  • minimize
  • needed
  • no-gpus
  • opt-flags
  • optmize
  • optimizer
  • random-seed
  • remote
  • stop-after

Refer to guild run for information on each option.

Step Check

A step check is a test that Guild applies to an operation step.

Checks are identified by a type attribute, which can be one of:

File Check Attributes


File path to check (required string)

Paths are considered relative to the step run directory.


Compares the run file to another file (string)

If the run file is different from the file specified by compare-to, the check fails.

Guild assumes that the compare-to file is relative to the step run directory.


Checks the run file for matching text (string)

contains must be a valid Python regular expression.

If the run file output does not contain text that matches this attribute value, the check fails.

Output Check Attributes


Pattern to search for in run output (required string)

If the run did not generate output that matches this value, the check fails.


In Guild AI, a model is a set of related operations.

Models are defined in full format Guild files using the model type attribute.

- model: svm
      main: train_svm

Model Attributes


Model name (string — required for model object type)

The model type attribute specifies the model name.


Description of the model (multiline string)

Use to provide a single line description as well as multiline descriptions. The first line of a model description is used in guild models output. Additional lines are used to show model help.


Model operations (mapping of operations

Use to define supported model operations. Mapping keys are operation names. See Operations for operation attributes.

Model operations are run using guild run MODEL:OPERATION where MODEL is the model name and OPERATION is the operation name.


Resources defined for the model (mapping of resources)

Use to define named resources, which can be referenced by operations as dependencies using the resource name (mapping key). See Resources for resource attributes.


Source code specification used for model operations (source code spec)

The sourcecode spec defined at the model level applies to all model operations. Operation level sourcecode specs extend the model level spec by appending items to the end of the model items.


Default Python requirement for model operations (string)

This value must be a valid pip install requirements spec.

Operations can redefine this value as needed using python-requires.


Mapping of attribute names to values

Use operation-detaults to provide a list of default operation attribute values. Operations that don’t otherwise define an attribute use the values specified here. This is useful, for example, for specifying a default output-scalars attribute for operations.


One or more models or config objects to extend (string or list of strings)

Use to inherit the a model definition from a model or config object.

For more information, see Inheritance below.


Mapping of parameter names to values

Use to define or redefine parameter values used in configuration.

For more information, see Parameters.


List of model sources and attributions (list of strings)

Guild includes model references in model help.


A Guild file can contain at most one top-level package object. A package object is identified by the use of the package attribute.

Guild uses package configuration when you run guild package. If a package object is not defined for a Guild file, Guild uses default values (see below).

Define a package when you want to:

  • Distribute your project as a Python distribution (e.g. on PyPI, etc.)
  • Include additional data files for remote runs
  • Control the package name and version associated with remote operations

Package Attributes


Package name (string — required for package object type)

The package type attribute specifies the package name.


Package version (string)

Defaults to 0.0.0.


Package description (string)

This can be a multi-line description.


URL to package website (string)


Name of individual or organization author (string)


Email of package author (string)


Name of package license (string)


List of package tags (list of strings)


Python tag used in the distribution name (string)


List of additional data files to include in the distribution (list of strings)

Guild always includes guild.yml, LICENSE.*, and README.*. The list of files specified by this attribute is added to this list.


Version of Python required by the package (string)


Requirements that must be satisfied when the package is installed (list of string)


Project Python packages to be included in the distribution (list of strings)

Default is the list of packages returned by setuptools find_packages().


A config top-level object can be used to create reusable configuration within a Guild file.

Use config objects to:

  • Define config that can be inherited by models
  • Define reusable sets of flags
  • Define reusable sets of operations


A model object can use extends to inherit attributes from one or more top-level objects. extends can be a string or a list of strings, each string referring to the top-level object name being inherited.

Inheriting from a single parent:

- model: child
  extends: parent

Inheriting from a multiple parents:

- model: child
    - parent-1
    - parent-2


Parents can use parameters in both attribute names and values. A parameter reference uses the format {{ NAME }}.

Parameter values are defined using the params model attribute. Parameters are inherited and can be redefined by children.

The following example illustrates the use of parameters to define flag value defaults.

- model: base
    default-lr: 0.1
    default-dropout: 0.2
        lr: '{{ default-lr }}'
        dropout: '{{ default-dropout }}'

- model: a
  extends: base

- model: b
  extends: base
    default-lr: 0.01
    default-dropout: 0.3

Important YAML formatting rules require that {{...}} be quoted when used at the start of a value. Note the single-quotes used in the example above.

Mapping Includes

A mapping include is a mapping key named $include. It’s used to include attributes into an object.

The value for $include can be a single string, which references the object to include. You can also specify a list of references.

The following attributes support mapping includes:

Reuse Flag Definitions

Include flags defined in other objects using the $include flag attribute.

- config: common-flags
    lr: 0.01
    dropout: 0.2

- operations:
        $include: common-flags
        layers: 2
        $include: common-flags
        kernel: linear

Reuse Operation Definitions

Include operations defined in other objects using the $include operation attribute.

- config: test-support
    test: test_model

- model: forest
    train: train_forest
    $include: test-support

- model: svm
    train: train_svm
    $include: test-support